Calculating weighted average using SUM function In Microsoft Excel, weighted average is calculated using the same approach but with far less effort because Excel functions will do most of the work for you. In this example, in order to calculate the weighted average (overall grade), you multiply each grade by the corresponding percentage (converted to a decimal), add up the 5 products together, and divide that number by the sum of 5 weights: In mathematics and statistics, you calculate weighted average by multiplying each value in the set by its weight, then you add up the products and divide the products' sum by the sum of all weights. However, we want the average formula to consider the weight of each activity listed in column C. A usual average is easily calculated with the Excel AVERAGE function. Students' grades are often calculated using a weighted average, as shown in the following screenshot. In other words, each value to be averaged is assigned a certain weight. Weighted average is a kind of arithmetic mean in which some elements of the data set carry more importance than others.

Average percentages calculator